A clinical investigation trial to analyze the role of interleukin-2 in the treatment of patients with cancer has been designed. This trial will test the toxicity of recombinant interleukin-2 preparations given subcutaneously, intramuscularly, or by slow intravenous infusion in escalating doses. Concomitantly, we will study the pharmacokinetics and immunomodulatory dose properties of recombinant interleukin-2 when given by these routes in escalating doses. Finally, in an attempt to evaluate the possible antitumor effects of interleukin-2 in cancer patients, we will administer the agent for three weeks on a daily basis at either the optimal immunomodulatory dose (as determined by our in vitro immunomonitoring assays) l/10 the optimal immunomodulatory dose or 10 x the optimal immunomodulatory dose, provided this dose is below the maximum tolerated dose (defined from previous toxicity testing).